Can I add another satellite, or extender to reach a garden office?
In general, these methods can be used to install WiFi in a building separate from the main house:
Just plug it in. This will work only if
The remote building is close enough to the main building to get a strong WiFi signal on the 5G band
Building materials do not block the 5G WiFi signal, or attenuate it too much.
There are reports of users locating an existing satellite in a window so it does not have to penetrate much wall structure and picking up a decent WiFi signal 50-100 ft. away.
Install an Ethernet cable between the main house and the outbuilding. Ethernet supports gigabit speed up to about 90 meters. (Technically 328 ft. including patch cords on both ends.) This is by far the #1 solution
Ethernet actually provides faster performance than WiFi backhaul because it is Full Duplex and avoids all the overhead inherent in WiFi radio communications.
Most users prefer to install Cat6 cable inside a PVC pipe in order to facilitate the installation process and to potentially replace the cable in the future.
Unfortunately, the installation is often more difficult and costly than the cable. Crossing concrete, walls, driveways, etc. Penetrating two building structures. etc. etc.
Use a wireless bridge. There have been many reports of using a pair of wireless units to imitate an Ethernet connection using radio. Installed in pairs, a wireless link appears to both ends to be an Ethernet cable. An Amazon search for "wireless bridge" will discover dozens of products.
Because they are rated in terms of kilometers, most will have enough signal strength to penetrate both the main building and the outbuilding walls. This avoids the cost and complexity of exterior mounting and weatherproofing cable penetrations.
They are available at a wide range of costs, from under $100 for a pair to several hundred.
Most of the least expensive are obviously knock-offs made in China by the factories that manufacture name brand products. I (personally) would be hesitant to buy products that have under 100 reviews Name brands such as Ubiquiti, TP-Link, D-Link, (and even Netgear) often get very good reviews.
There are tons of videos on the web showing how to deploy wirless bridges.
The choice of what to place in the outbuilding is up to the customer:
Putting an Orbi satellite compatible with the main system creates a "seamless" WiFi environment, where devices will roam back and forth automatically. This may be costly.
Any WiFi access point, of any brand, could be installed in the remote building. It could have the same WiFi credentials as the Orbi system, so that products will connect to it automatically. (Or, it could have different credentials. After a device has connected once, it will connect automatically again in the future. The difference is that devices may not think the WiFi connection has dropped off enough that they should look for a new one. The result (no matter what credentials are used) is that the user will mutter, "why's my phone so SLOW??? Oh, damn. I need to disconnect WiFi and reconnect."
